I would have done this earlier but I had a very busy weekend.
This series premiere knocked the wind out of me and for me it was one of the scariest episodes ever of Supernatural. I loved it.
Just as I thought we finally got Cas back he turns horribly into a Leviathan right before our eyes. So that's why he was getting kind of wonky during the episode. They were working their way out to the surface.
Sam, Dean and Bobby are going to have a heck of a time this season with Cas or whoever he has turned into, and I just hope that it all turns out okay but after seeing the season 7 premiere, I wouldn't be on it.
Here are some screen caps I made from this episode.